a footnote. Japanese didn't round up allied citizens immediately after they took over International Settlement. At first, only British and American adult citizens were ordered for register (British: 2681 male and 2412 female, American: 700 male and 477 female). Their factories, warehouses, bank accounts and real estates were registered too, later be frozen or confiscated (same were Belgian properties).
Since March 1 1942, Japan began to exchange civilians with US. After October 1 1942, "hostile citizens" were ordered to wear red armband to identify. There's a letter on the armband, "A" for America, "B" for British, "N" for netherlands, others were "X". These "hostile citizen" were forbided enter theaters, cinemas, bars, clubs and bars since Oct 15 1942. Later French Settlement also forbided American and British citizens enter its parks and theaters. After Nov 13, all properties of hostile citizen were confiscated, from radio, camera and furniture to fan and stove.
According to Japanese, those "hostile citizens" incude citizens of UK, US, Australia, Canada, New Zealand, South Africa, Belgium, Netherland, Haiti, Costa Rica, Honduras, Guatemala, Nicaragua, Dominica, Cuba and Panama. But citizens of Brazil, Mexico, Columbia, Iran, Iraq and Greece were not "hostile citizens", although these countries declared war against Axis in 1942 and 1943.
The round up of Allied citizens began on Feb 15 1943.